AMT vs IRM
American Tower Corp /Ma/ (AMT) and Iron Mountain Inc (IRM) are both filed with the SEC under Real Estate Investment Trusts. AMT is 2.2× IRM's size by market cap ($81.1B against $36.5B); IRM trades at the higher fiscal-year P/E (250.4× against 32.3×); AMT reports the higher net margin (24.7% against 2.2%); IRM grew sales faster over three years (+10.6% against +3.3%); and over the past year IRM returned +31.1% against AMT's -9.6%.
| AMT | IRM | |
|---|---|---|
| Last close | $176.23 | $117.40 |
| Market cap | $81.1B | $36.5B |
| P/E (FY) | 32.3× | 250.4× |
| P/S | 7.6× | 5.3× |
| EV/EBITDA | 17.0× | 24.1× |
| Operating margin | 45.5% | 16.9% |
| Net margin | 24.7% | 2.2% |
| Return on equity | 74.7% | — |
| Sales growth (3y) | +3.3% | +10.6% |
| EPS growth (3y) | +12.2% | -36.3% |
| Dividend yield | 3.9% | 2.5% |
| 1-year return | -9.6% | +31.1% |
Screener snapshot — prices as of 2026-08-28. Each side's last close is the most recent session the snapshot holds for that company, which can be an earlier one, and its 1-year return is measured to that close. Market caps struck on 2026-08-27. Last close, market cap and the 1-year return are price figures; every other row is computed over the company's latest filed fiscal year — FY2025 (ended 2025-12-31) for both. — not published for this company. A ratio goes unpublished for more than one reason: a component the calculation needs is not on file, the filing does not tag the line it is read from, or the calculation is not defined on the filed basis — EV/EBITDA is not printed on non-positive EBITDA, and return on equity is not computed on a zero or negative equity base.
Who holds them, and who has traded them
| AMT | IRM | |
|---|---|---|
| Institutional holders (13F) | 1,739 | 1,079 |
| Insider buyers − sellers (180d) | -2 | -5 |
| Congressional trades disclosed (180d) | 3 | 0 |
| Executive-branch officials on file — trades disclosed (180d) | 8 | 3 |
Counts only. The congressional figures count transactions dated in the trailing 180 days and disclosed in STOCK Act periodic transaction reports; amounts are filed as ranges and are never summed. The executive-branch figures count the same window of transactions, and they are scoped to one roster. The officials OGE posts for direct download. Insider buyers − sellers counts distinct people filing open-market Form 4 purchases minus distinct people filing open-market sales over the trailing 180 days, capped at ±5.
AMT vs IRM: common questions
- Is AMT bigger than IRM?
- AMT carries the larger market cap — $81.1B against $36.5B, both struck on 2026-08-27.
- Which trades at a higher P/E, AMT or IRM?
- IRM, at a fiscal-year 250.4× against 32.3× for AMT. Both are price ÷ latest full-year diluted earnings per share, not a trailing-twelve-month P/E.
- How have AMT and IRM performed over the past year?
- IRM returned +31.1% and AMT -9.6%, measured on the trailing calendar year to the last close.
- How many institutions hold AMT and IRM?
- 1,739 13F filers report a position in AMT and 1,079 in IRM, on the latest quarter in the panel.
- Are AMT and IRM in the same industry?
- Both are filed with the SEC under Real Estate Investment Trusts, which is the classification this pairing is built on.
AMT overview → · IRM overview → · AMT institutional ownership → · IRM institutional ownership → · Congress and AMT → · Executive branch and AMT → · Executive branch and IRM →
More in Real Estate Investment Trusts: AMT vs DLR · AMT vs EQIX · AMT vs PLD · AMT vs SPG
Stock comparisons lists every pair this site publishes.
Source: SPZCO — https://spzco.com/vs/amt-vs-irm